Arguments that detractors of Christianity need to quit using: (because they make them look like idiots)
1:"The Bible has lots of depictions of horrible stuff, that's a reason why it's bad."
My high school history book had a section about the holocaust. I didn't reason that it meant the writer was a Nazi. Why? Oh yeah, because that would be stupid.
2:"The Bible wasn't even written until *insert time that supposedly demonstrates disassociation with Biblical account*"
Actually, the Bible is the most well-documented ancient book in existence, with more original copies from time of antiquity recorded than The Iliad and The Odyssey (and many other famous books) combined. Due to historical documentation, it was clearly shown to be written at the time that its proponents claim it to have been.
3:"Christians committed some of the worst atrocities that ever happened. Hitler and Stalin were Christians."
I could claim to be a pantheistic Islamic Buddhist and go burn down a local donut shop in the name of Thor, the god of thunder. Does that make me a true believer in anything? Does that make me an example of what a true follower of my self-proclaimed belief is? No, it means I'm a lunatic.
I have more, but these were just the ones that have most frequently been used on me that I get SO tired of hearing and explaining to the slack-jawed idiots (yeah yeah, love thy enemy...) who think they're so clever for using their 'logic'...